Small amounts used to sweeten foods are fine, preferably at mealtimes, so there is less risk of damaging your teeth. However, many of us have too many high-sugar foods and drinks too often.

Added sugar is not necessary for a healthy diet, and sugar-sweetened beverages have been linked to obesity, especially in children. The Government’s Scientific Advisory Committee on Nutrition (SACN) published an extensive review of the science on carbohydrate in July 2015, and made recommendations about how people should improve their diets so as to have a better balance of carbohydrate foods, especially “free sugars”.

What are 'free sugars'?

Free sugars are those added to food (e.g. sucrose (table sugar), glucose) or those naturally present in honey, syrups and unsweetened fruit juices, but exclude lactose in milk and milk products as well as those sugars contained in fruit that is still intact – i.e. not juiced. SACN has recommended that free sugars account for no more than 5% of daily energy intake.

This is equivalent to:

19g or 5 sugar cubes for children aged 4 to 6

24g or 6 sugar cubes for children aged 7 to 10

30g or 7 sugar cubes for 11

Why is sugar such an issue?

The SACN Report found that high intakes of sugar were associated with greater risk of tooth decay and obesity. Sugar-sweetened beverages (sugar-rich drinks) in particular were shown to increase Body Mass Index (BMI) in teenagers – this age group tends to drink the highest volume of sugary drinks.

There is also some research that suggests that having too much sugar in the form of sugar-sweetened beverages increases the risk of type 2 diabetes.

What kinds of food and drink tend to be high in sugar?

Drinks are also a major source of sugar. Sugars added to food or drink can be listed in various ways including sucrose, glucose, syrup, dextrose, honey, fructose, treacle, molasses, lactose, corn syrup or fruit juice concentrates.

How can I tell if a food is high in sugar?

If one of the various forms of sugar is high up the ingredient list, it will be high in sugar. Another way is to look on the nutrition information panel (on the back of the packet), which lists ‘sugars’. This figure is based on all the forms of sugar in the product, added together, to give a total. It is listed ‘per 100g’ (or per 100mls for drinks), and ‘per serving’.

High-sugar food contains more than 22.5g per 100g, and a low-sugar food contains less than 5g per 100g. A high-sugar drink contains more than 11.25g per 100ml, and a low-sugar drink contains less than 2.5g. As well as these figures, there is also a high-sugar cutoff point to show food and drinks where a normal portion would lead to eating or drinking a high level of sugar.

These foods and drinks are also labelled as high in sugar(red) if they contain high levels of sugar in a normal portion size regardless of their sugar content per 100mls. Some products include colour-coded labelling (on the front of the packet) showing colour-coded levels of energy, fat, saturated fat, sugar and salt per serving. Red means high, amber means medium, and green means low.

How can I tell if a food is high in free sugars?

Not easily at the moment! Food labels don’t currently differentiate between free sugars and other sugars like milk sugar (lactose). Further, sugar naturally present in fruit and vegetables that may be in a food product (such as fruit pie or vegetable lasagne) would not be considered as free sugars since they are still an intrinsic part of the fruit or veg. So working out how much free sugars you have in a day isn’t easy.

Typically, sugar-sweetened beverages like fizzy soft drinks and confectionery items such as sweets and chocolates are rich in free sugars, so it’s best to keep these to a minimum. And as a general rule, if you limit the amount of sugar-rich food and drink you eat in a day, you’ll be cutting down on your free sugars.

How might a high-sugar diet affect your health?

In nature, sugar usually comes with fibre, vitamins, minerals and water – this combination is not harmful and is generally good for us. Fresh fruit, peas, and sweetcorn are good examples. Some processed foods can be surprisingly high in free sugars.

Some experts believe the liver handles high intakes of sugar in a way that is damaging to our health, especially if we are overweight or not physically active. This could lead to an increased risk of diabetes, heart disease and other health problems. Also, many high-sugar foods are low in nutrients and fibre.

This means that a high-sugar diet can be low in nutritional value. So, it’s important to consider the whole food and not just the sugar. Some foods that contain sugar come with added nutrients, and these micronutrients can from an important part of the diet. A yogurt, for example, will deliver protein and calcium. A fruit and veg smoothie will give you fibre and potassium. Fruit juice brings with it vitamin C and potassium.

The problem is the amount we tend to eat or drink! Keep an eye on your portion size. With fruit juice, one small 150ml glass of unsweetened fruit juice counts once towards your five a day fruit and veg intake. And when it comes to soft drinks or yogurts, look out for lower sugar or diet versions.

Does sugar make you overweight?

A small amount of sugar will not make you overweight. A high-sugar diet, typical of many people, may make excess weight gain more likely if overall calorie (energy) intake is higher than the body needs. High-sugar diets are not the only cause of weight gain: too much energy from any source will make you put on weight.

A high sugar intake, leading to excess energy intake, is linked to weight gain in both children and adults. Sugary drinks are thought to be the biggest problem, as they tend to be low in fibre. Fruit or vegetable smoothies do provide fibre, but you still need to watch your portion size as they contribute to your free sugars intake.

It’s far easier to drink a large amount of fruit juice or a smoothie compared to eating whole fruit, so keep to recommended portion sizes. Also, some experts believe that the hormones controlling our sense of hunger and fullness respond differently to a high-sugar diet (from drink or food).

Will sugar rot my teeth?

High sugar intakes often lead to tooth decay. It is important to avoid frequent sugary drinks and snacks for your teeth and your overall health.

If you want something sugary, it is best to have it at mealtimes. Fresh fruit as a snack between meals is fine, but the ‘free’ acid and sugars in pure fruit juices can damage teeth, so it’s best to drink them in limited amounts and only with a meal.

‘Diet’ soft drinks contain little or no sugar; however, most are still acidic enough to harm your teeth if consumed too often. Water and milk, or unsweetened tea or coffee are the best choices for a drink between meals.

Do sugary drinks make children hyperactive?

There is no evidence that the sugar in drinks contributes to hyperactivity in children or that it affects mood, attention or behaviour.

A few high-sugar products still use colourings that affect some children’s behaviour but most companies have removed these now. If they are used, there will be a warning on the label that the colouring used ‘may have an adverse effect on activity and attention in children’.

Is it okay to give sweetened drinks to children?

They are not the best choice for children. If they drink fizzy drinks or squashes too often, they might find it hard to appreciate the subtle sweetness of berries, peas, sweetcorn or other naturally sweet, nutritious foods.

Sugary drinks can provide excess energy and unnecessary weight gain and/or they will replace something more nutritious. Dilute any sweet drinks, including fruit juice, with water where possible, and offer at mealtimes only. Please be aware that ‘energy drinks’ contain caffeine as well as sugar and should not be consumed by children under 16 years of age.

Sugar in fruit

Fruit contains fibre, vitamins, minerals and some sugar. It is a healthy alternative to foods high in free sugars and fat. Although pure fruit juices and smoothies are unsweetened and the sugar comes naturally from fruit, they still provide free sugars, as well as some vitamins and minerals.

Fruit juice will not maintain the fibre from the whole pieces of fruit. A small 150ml glass, once a day, is fine.

Summary

In nature, foods containing sugars usually also contain fibre, vitamins and minerals and water. Fruit and some vegetables are good examples of foods we should be eating more of, but which also contain sugar naturally.

A limited intake of sugar is not harmful. However, many people in the UK have too many high-sugar foods and drinks in their diet too often, which is a risk to their dental health and, alongside an excess in total energy intake, has been linked to diabetes, heart disease and weight gain.

This Food Factsheet is a public service of The British Dietetic Association (BDA) intended for information only. It is not a substitute for proper medical diagnosis or dietary advice given by a dietitian. If you need to see a dietitian, visit your GP for a referral or a private dietitian.